System and methods for handling priority services congestion

ABSTRACT

Techniques for congestion management in a communication network are contemplated. For example, a wireless transmit receive unit (WTRU) may include a Radio Resource Control (RRC) layer and a Non-Access Stratum (NAS) layer. The RRC layer may receive an indication for a service, for example from the NAS. The indication may be interpreted as a request for the particular service indicated. For example, the indicated service may correspond to at least one of: a mobile originated (MO) voice communication, a circuit switched fallback (CSFB) supplementary service (SS), or a MO short message service (SMS). The RRC layer may receive a signal from a network indicating that one or more services provided by the network are allowed. The RRC layer may send a connection request to the network for the service sought by the NAS if that service is one of the one or more services allowed.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is the National Stage entry under 35 U.S.C. § 371 ofPatent Cooperation Treaty Application PCT/US2014/063261, titled “SYSTEMAND METHODS FOR HANDLING PRIORITY SERVICES CONGESTION”, filed Oct. 30,2014, which claims the benefit of U.S. Provisional Application No.61/897,810, titled “SYSTEM AND METHODS FOR HANDLING PRIORITY SERVICESCONGESTION”, filed Oct. 30, 2013, the contents of all of which areincorporated by reference as if fully set-forth herein in is theirrespective entirety, for all purposes.

BACKGROUND

3GPP based networks, among other communication networks, may experiencecongestion, including congestion corresponding to the communicationtraffic associated with services and/or procedures. The large number ofnetwork devices (e.g., cellular smart phones operated in ever more densenetworks) and the corresponding network traffic they generate may alsocontribute to communication network congestion. For example, videostreaming, small data transmissions, voice transmissions, and/ormultimedia transmissions, and/or the like, and the network services thatsupport such transmissions may all contribute to network congestion.Important transmissions (e.g., emergency transmissions) could benegatively impacted by what may be stiff competition for transmissionresources and/or services in congested networks.

SUMMARY

The Summary is provided to introduce a selection of concepts in asimplified form that are further described below in the DetailedDescription. This Summary is not intended to identify key featuresand/or essential features of the claimed subject matter, nor is itintended to be used to limit the scope of the claimed subject matter.

Systems, methods, and instrumentalities are provided to describecongestion management in a network. A wireless transmit receive unit(WTRU) may set a unique establishment cause or a unique serviceindication to differentiate a service. The service may be one of: amobile originated (MO) voice communication, a MO circuit switchedfallback (CSFB) voice, CSFB supplementary service (SS), or a MO shortmessage service (SMS). The WTRU may send a service request messagecomprising a request for connection of the service to a base station.The WTRU may receive a response message in response to the servicerequest. The response message indicates acceptance or rejection of therequest for the connection of the service.

Embodiments contemplate one or more techniques for a wirelesstransmit/receive unit (WTRU) that may be in communication with acommunication network and/or may include a Radio Resource Control (RRC)layer. The RRC layer may receive a first message, where the firstmessage may include an indication for a service. The RRC layer mayreceive a second message, where the second message may indicate one ormore services allowable by the communication network. The service may bedetermined to be one of the one or more services allowable by thecommunication network. The RRC layer may send a connection request forthe service upon the service being one of the one or more servicesallowable by the communication network.

Embodiments contemplate one or more techniques for a wirelesstransmit/receive unit (WTRU) that may be in communication with acommunication network and/or may include a Radio Resource Control (RRC)layer. The RRC layer may receive a first message, where the firstmessage may include an indication for a service. The RRC layer mayreceive a second message, where the second message may indicate one ormore services allowable by the communication network. The service may bedetermined to not be one of the one or more services allowable by thecommunication network. The RRC layer may refrain from sending aconnection request for the service upon the service not being one of theone or more services allowable by the communication network.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of example embodiments is providedwith reference to the appended drawings. For the purposes ofillustration, the drawings show example embodiments. The contemplatedsubject matter is not limited to the specific elements and/orinstrumentalities described or illustrated. And absent specific notationto the contrary, no subject matter is contemplated as necessary and/oressential. In addition, the described embodiments may be employed in anycombination, in whole or in part. In the drawings:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented.

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A.

FIG. 1C is a system diagram of an example radio access network and anexample core network that may be used within the communications systemillustrated in FIG. 1A.

FIG. 1D is a system diagram of another example radio access network andan example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 1E is a system diagram of another example radio access network andan example core network that may be used within the communicationssystem illustrated in FIG. 1A.

FIG. 2 is a diagram of an example of a service prioritization/barringtechnique, consistent with embodiments.

FIG. 3 is a diagram of an example of a service prioritization/barringtechnique, consistent with embodiments.

DETAILED DESCRIPTION

A detailed description of example embodiments will now be described withreference to the various Figures. Although this description provides adetailed example of possible implementations, it should be noted thatthe details are intended to be examples and in no way limit the scope ofthe application. As used herein, the article “a” or “an”, absent furtherqualification or characterization, may be understood to mean “one ormore” or “at least one”, for example. Also, as used herein, the phraseuser equipment (UE) may be understood to mean the same thing as thephrase wireless transmit/receive unit (WTRU).

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, and/or 102 d (whichgenerally or collectively may be referred to as WTRU 102), a radioaccess network (RAN) 103/104/105, a core network 106/107/109, a publicswitched telephone network (PSTN) 108, the Internet 110, and othernetworks 112, though it will be appreciated that the disclosedembodiments contemplate any number of WTRUs, base stations, networks,and/or network elements. Each of the WTRUs 102 a, 102 b, 102 c, 102 dmay be any type of device configured to operate and/or communicate in awireless environment. By way of example, the WTRUs 102 a, 102 b, 102 c,102 d may be configured to transmit and/or receive wireless signals andmay include user equipment (UE), a mobile station, a fixed or mobilesubscriber unit, a pager, a cellular telephone, a personal digitalassistant (PDA), a smartphone, a laptop, a netbook, a personal computer,a wireless sensor, consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106/107/109, theInternet 110, and/or the networks 112. By way of example, the basestations 114 a, 114 b may be a base transceiver station (BTS), a Node-B,an eNode B, a Home Node B, a Home eNode B, a site controller, an accesspoint (AP), a wireless router, and the like. While the base stations 114a, 114 b are each depicted as a single element, it will be appreciatedthat the base stations 114 a, 114 b may include any number ofinterconnected base stations and/or network elements.

The base station 114 a may be part of the RAN 103/104/105, which mayalso include other base stations and/or network elements (not shown),such as a base station controller (BSC), a radio network controller(RNC), relay nodes, etc. The base station 114 a and/or the base station114 b may be configured to transmit and/or receive wireless signalswithin a particular geographic region, which may be referred to as acell (not shown). The cell may further be divided into cell sectors. Forexample, the cell associated with the base station 114 a may be dividedinto three sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 115/116/117,which may be any suitable wireless communication link (e.g., radiofrequency (RF), microwave, infrared (IR), ultraviolet (UV), visiblelight, etc.). The air interface 115/116/117 may be established using anysuitable radio access technology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 103/104/105 and the WTRUs 102a, 102 b, 102 c may implement a radio technology such as UniversalMobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA),which may establish the air interface 115/116/117 using wideband CDMA(WCDMA). WCDMA may include communication protocols such as High-SpeedPacket Access (HSPA) and/or Evolved HSPA (HSPA+). HSPA may includeHigh-Speed Downlink Packet Access (HSDPA) and/or High-Speed UplinkPacket Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface115/116/117 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1×, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106/107/109.

The RAN 103/104/105 may be in communication with the core network106/107/109, which may be any type of network configured to providevoice, data, applications, and/or voice over internet protocol (VoIP)services to one or more of the WTRUs 102 a, 102 b, 102 c, 102 d. Forexample, the core network 106/107/109 may provide call control, billingservices, mobile location-based services, pre-paid calling, Internetconnectivity, video distribution, etc., and/or perform high-levelsecurity functions, such as user authentication. Although not shown inFIG. 1A, it will be appreciated that the RAN 103/104/105 and/or the corenetwork 106/107/109 may be in direct or indirect communication withother RANs that employ the same RAT as the RAN 103/104/105 or adifferent RAT. For example, in addition to being connected to the RAN103/104/105, which may be utilizing an E-UTRA radio technology, the corenetwork 106/107/109 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106/107/109 may also serve as a gateway for the WTRUs102 a, 102 b, 102 c, 102 d to access the PSTN 108, the Internet 110,and/or other networks 112. The PSTN 108 may include circuit-switchedtelephone networks that provide plain old telephone service (POTS). TheInternet 110 may include a global system of interconnected computernetworks and devices that use common communication protocols, such asthe transmission control protocol (TCP), user datagram protocol (UDP)and the internet protocol (IP) in the TCP/IP internet protocol suite.The networks 112 may include wired or wireless communications networksowned and/or operated by other service providers. For example, thenetworks 112 may include another core network connected to one or moreRANs, which may employ the same RAT as the RAN 103/104/105 or adifferent RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 130, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment. Also, embodiments contemplate that thebase stations 114 a and 114 b, and/or the nodes that base stations 114 aand 114 b may represent, such as but not limited to transceiver station(BTS), a Node-B, a site controller, an access point (AP), a home node-B,an evolved home node-B (eNodeB), a home evolved node-B (HeNB), a homeevolved node-B gateway, and proxy nodes, among others, may include someor all of the elements depicted in FIG. 1B and described herein.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 115/116/117. For example, in one embodiment,the transmit/receive element 122 may be an antenna configured totransmit and/or receive RF signals. In another embodiment, thetransmit/receive element 122 may be an emitter/detector configured totransmit and/or receive IR, UV, or visible light signals, for example.In yet another embodiment, the transmit/receive element 122 may beconfigured to transmit and receive both RF and light signals. It will beappreciated that the transmit/receive element 122 may be configured totransmit and/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 115/116/117.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 130 and/or the removable memory 132.The non-removable memory 130 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 115/116/117from a base station (e.g., base stations 114 a, 114 b) and/or determineits location based on the timing of the signals being received from twoor more nearby base stations. It will be appreciated that the WTRU 102may acquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 103 and the core network 106according to an embodiment. As noted above, the RAN 103 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 115. The RAN 103 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 103 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 115. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 103. TheRAN 103 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 103 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC 142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macro diversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 103 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 103 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1D is a system diagram of the RAN 104 and the core network 107according to an embodiment. As noted above, the RAN 104 may employ anE-UTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102c over the air interface 116. The RAN 104 may also be in communicationwith the core network 107.

The RAN 104 may include eNode-Bs 160 a, 160 b, 160 c, though it will beappreciated that the RAN 104 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 160 a, 160 b, 160c may each include one or more transceivers for communicating with theWTRUs 102 a, 102 b, 102 c over the air interface 116. In one embodiment,the eNode-Bs 160 a, 160 b, 160 c may implement MIMO technology. Thus,the eNode-B 160 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 102 a.

Each of the eNode-Bs 160 a, 160 b, 160 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1D, theeNode-Bs 160 a, 160 b, 160 c may communicate with one another over an X2interface.

The core network 107 shown in FIG. 1D may include a mobility managementgateway (MME) 162, a serving gateway 164, and a packet data network(PDN) gateway 166. While each of the foregoing elements are depicted aspart of the core network 107, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 162 may be connected to each of the eNode-Bs 160 a, 160 b, 160 cin the RAN 104 via an S1 interface and may serve as a control node. Forexample, the MME 162 may be responsible for authenticating users of theWTRUs 102 a, 102 b, 102 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 102 a,102 b, 102 c, and the like. The MME 162 may also provide a control planefunction for switching between the RAN 104 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 164 may be connected to each of the eNode-Bs 160 a,160 b, 160 c in the RAN 104 via the S1 interface. The serving gateway164 may generally route and forward user data packets to/from the WTRUs102 a, 102 b, 102 c. The serving gateway 164 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 102 a,102 b, 102 c, managing and storing contexts of the WTRUs 102 a, 102 b,102 c, and the like.

The serving gateway 164 may also be connected to the PDN gateway 166,which may provide the WTRUs 102 a, 102 b, 102 c with access topacket-switched networks, such as the Internet 110, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and IP-enableddevices.

The core network 107 may facilitate communications with other networks.For example, the core network 107 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices. For example, the corenetwork 107 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 107 and the PSTN 108. In addition, the corenetwork 107 may provide the WTRUs 102 a, 102 b, 102 c with access to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1E is a system diagram of the RAN 105 and the core network 109according to an embodiment. The RAN 105 may be an access service network(ASN) that employs IEEE 802.16 radio technology to communicate with theWTRUs 102 a, 102 b, 102 c over the air interface 117. As will be furtherdiscussed below, the communication links between the differentfunctional entities of the WTRUs 102 a, 102 b, 102 c, the RAN 105, andthe core network 109 may be defined as reference points.

As shown in FIG. 1E, the RAN 105 may include base stations 180 a, 180 b,180 c, and an ASN gateway 182, though it will be appreciated that theRAN 105 may include any number of base stations and ASN gateways whileremaining consistent with an embodiment. The base stations 180 a, 180 b,180 c may each be associated with a particular cell (not shown) in theRAN 105 and may each include one or more transceivers for communicatingwith the WTRUs 102 a, 102 b, 102 c over the air interface 117. In oneembodiment, the base stations 180 a, 180 b, 180 c may implement MIMOtechnology. Thus, the base station 180 a, for example, may use multipleantennas to transmit wireless signals to, and receive wireless signalsfrom, the WTRU 102 a. The base stations 180 a, 180 b, 180 c may alsoprovide mobility management functions, such as handoff triggering,tunnel establishment, radio resource management, traffic classification,quality of service (QoS) policy enforcement, and the like. The ASNgateway 182 may serve as a traffic aggregation point and may beresponsible for paging, caching of subscriber profiles, routing to thecore network 109, and the like.

The air interface 117 between the WTRUs 102 a, 102 b, 102 c and the RAN105 may be defined as an R1 reference point that implements the IEEE802.16 specification. In addition, each of the WTRUs 102 a, 102 b, 102 cmay establish a logical interface (not shown) with the core network 109.The logical interface between the WTRUs 102 a, 102 b, 102 c and the corenetwork 109 may be defined as an R2 reference point, which may be usedfor authentication, authorization, IP host configuration management,and/or mobility management.

The communication link between each of the base stations 180 a, 180 b,180 c may be defined as an R8 reference point that includes protocolsfor facilitating WTRU handovers and the transfer of data between basestations. The communication link between the base stations 180 a, 180 b,180 c and the ASN gateway 182 may be defined as an R6 reference point.The R6 reference point may include protocols for facilitating mobilitymanagement based on mobility events associated with each of the WTRUs102 a, 102 b, 102 c.

As shown in FIG. 1E, the RAN 105 may be connected to the core network109. The communication link between the RAN 105 and the core network 109may defined as an R3 reference point that includes protocols forfacilitating data transfer and mobility management capabilities, forexample. The core network 109 may include a mobile IP home agent(MIP-HA) 184, an authentication, authorization, accounting (AAA) server186, and a gateway 188. While each of the foregoing elements aredepicted as part of the core network 109, it will be appreciated thatany one of these elements may be owned and/or operated by an entityother than the core network operator.

The MIP-HA may be responsible for IP address management, and may enablethe WTRUs 102 a, 102 b, 102 c to roam between different ASNs and/ordifferent core networks. The MIP-HA 184 may provide the WTRUs 102 a, 102b, 102 c with access to packet-switched networks, such as the Internet110, to facilitate communications between the WTRUs 102 a, 102 b, 102 cand IP-enabled devices. The AAA server 186 may be responsible for userauthentication and for supporting user services. The gateway 188 mayfacilitate interworking with other networks. For example, the gateway188 may provide the WTRUs 102 a, 102 b, 102 c with access tocircuit-switched networks, such as the PSTN 108, to facilitatecommunications between the WTRUs 102 a, 102 b, 102 c and traditionalland-line communications devices. In addition, the gateway 188 mayprovide the WTRUs 102 a, 102 b, 102 c with access to the networks 112,which may include other wired or wireless networks that are owned and/oroperated by other service providers.

Although not shown in FIG. 1E, it will be appreciated that the RAN 105may be connected to other ASNs and the core network 109 may be connectedto other core networks. The communication link between the RAN 105 theother ASNs may be defined as an R4 reference point, which may includeprotocols for coordinating the mobility of the WTRUs 102 a, 102 b, 102 cbetween the RAN 105 and the other ASNs. The communication link betweenthe core network 109 and the other core networks may be defined as an R5reference, which may include protocols for facilitating interworkingbetween home core networks and visited core networks.

In a 3GPP based networks, for example, congestion mitigation and/orprioritization of services may be provided. In some cases, someservices/procedures may have lower priority or might not be allowed atall, while other services may be given higher priority. An evolved NodeB (eNB), however, might not be able to distinguish radio resourcecontrol (RRC) connection requests including requests for the servicesthat may have lower priority (or perhaps not allowed at all) from theones that may have higher priority. Embodiments contemplate that it maybe useful to differentiate the radio resource control (RRC) connectionrequests of various types of services at the eNB.

Considerations for congestion mitigation and/or prioritization ofcertain services in mobile networks (e.g., 3GPP based mobile networks)may be provided. In some cases, one or more services and/or proceduresmight not be allowed in the system (e.g., mobile originated signalingfor user data) or may be given a lower priority, while other servicesmay be given a higher priority (e.g., emergency services over packetswitched (PS) or circuit switched (CS) domains). One or more barringmechanisms may be provided such as access class barring (ACB), servicespecific access barring (SSAB) (e.g., to implement reduction in circuitswitched fallback (CSFB) request), and/or extended access barring (EAB)(e.g., to reduce the number of access attempts made by devices that areconsidered to be low access priority devices (LAPD)).

Congestion and/or prioritization of use of one or more services may beprovided. For example, a MO voice communication request, IMS voice orCSFB requests, or the like, may be prioritized over other IP data (e.g.,video stream and/or browsing data). Congestion mitigation handlingmechanisms in RRC_IDLE and RRC_CONNECTED may be improved, for example toprovide prioritization of the mobile originating accesses duringcongestion (e.g., emergency access, high priority access, etc.).Prioritization of mobile originating access (e.g., access for initiationof voice services such as MO voice communication, MMTEL voice calls,and/or CSFB voice calls) may be provided during congestion, for exampleperhaps based on an operator's policy and/or other scenario.

A wireless transmit receive unit (WTRU) in an LTE network may haveaccess to CS service such as SMS, and/or CS voice calls and/orsupplementary services (SS). The SMS service may be natively providedusing NAS signaling. For example, SMS messages may be sent via LTE NASmessages that may act as a transport for the message. The CS voice callsmay be made available via CSFB, for example in which a WTRU may requestto perform an intersystem change (e.g., using the NAS Extended ServiceRequest (ESR) message). In some embodiments, the CS voice call may beplaced in GERAN/UTRAN, perhaps for example after the intersystem change.The WTRU might not receive a service, e.g., perhaps for example when theWTRU is in idle mode and/or when the WTRU is not in a connected mode.The WTRU may establish an RRC connection for which an establishmentcause may be passed to the eNB, for example so that the eNB may know thereason for the connection request and/or act upon it (e.g., accept orreject the request). The establishment cause that the WTRU may use maycorrespond to the procedure that the WTRU may be requesting (e.g., theindicated service). The NAS layer may verify the establishment cause (orthe indicated service) and/or corresponding procedure. The NAS layer maypass the establishment cause or a service indication to the RRC layer.Table 1 illustrates the establishment causes that may be used, forexample when the Service Request/Service Indication is initiated. TheWTRU may transition to connected mode, for example at service requestinitiation, perhaps in order to send an SMS, request a CSFB, and/orrequest use of resources for IP data, etc.

TABLE 1 NAS procedure RRC establishment cause Call type Service Request/If a SERVICE REQUEST is to request user plane radio “originating ServiceIndication resources, the RRC establishment cause may be set to calls”MO data. If a SERVICE REQUEST is to request user plane radio “emergencyresources for emergency bearer services, the RRC calls” establishmentcause may be set to Emergency call. If a SERVICE REQUEST is to requestresources for UL “originating signalling, the RRC establishment causemay be set to calls” MO data. If a SERVICE REQUEST is triggered by a PDN“emergency CONNECTIVITY REQUEST that has request type set to calls”“emergency”, the RRC establishment cause may be set to Emergency call.If a SERVICE REQUEST is a response to paging where “terminating the CNdomain indicator is set to “PS”, the RRC calls” establishment cause maybe set to MT access. If an EXTENDED SERVICE REQUEST has service type“emergency set to “packet services via S1” and is to request user planecalls” radio resources for emergency bearer services, the RRCestablishment cause may be set to Emergency call. If an EXTENDED SERVICEREQUEST has service type “emergency set to “packet services via S1” andis triggered by a PDN calls” CONNECTIVITY REQUEST that has request typeset to “emergency”, the RRC establishment cause may be set to Emergencycall. If an EXTENDED SERVICE REQUEST has service type “terminating setto “packet services via S1” and is a response to paging calls” where theCN domain indicator is set to “PS”, the RRC establishment cause may beset to MT access. If an EXTENDED SERVICE REQUEST has service type“originating set to “mobile originating CS fallback or 1xCS fallback”calls” and is to request mobile originating 1xCS fallback, the RRCestablishment cause may be set to MO data. If an EXTENDED SERVICEREQUEST has service type “mobile set to “mobile originating CS fallbackor 1xCS fallback” originating CS and is to request mobile originating CSfallback, the RRC fallback” establishment cause may be set to MO data.If an EXTENDED SERVICE REQUEST is a response to “terminating paging forCS fallback, service type set to “mobile calls” terminating CS fallbackor 1xCS fallback”, the RRC establishment cause may be set to MT access.If an EXTENDED SERVICE REQUEST has service type “emergency set to“mobile originating CS fallback emergency call or calls” 1xCS fallbackemergency call”, the RRC establishment cause may be set to Emergencycall. If an EXTENDED SERVICE REQUEST contains the “originating Deviceproperties IE with low priority indicator set to calls” “MS isconfigured for NAS signalling low priority”, the RRC establishment causemay be set to Delay tolerant.

Some embodiments recognize that an eNB might not differentiate betweenrequests for SMS from a WTRU and IP Data. As illustrated in Table 1, forexample, the WTRU (e.g., NAS) may set the service indication orestablishment cause to MO data, perhaps for example if the servicerequest procedure may be initiated for CSFB, SMS transmission, and/oruser plane resources. Some embodiments recognize that the eNB might notdifferentiate between the RRC connection requests and might not be ableto apply the appropriate barring and/or prioritization mechanism(s). Toenhance the system performance, reduce congestion, and/or to prioritizeone or more services (e.g., MO voice communication), embodimentscontemplate that it may be useful to differentiate requests at the eNBso that the request may be treated, perhaps for example, based on acongestion level on the system and/or the eNB, among other scenarios.For example, the eNB may be configured to allow MO voice calls, whereasSMS might be not allowed (or may be provided a lower relative prioritythan the MO voice calls) in times of (e.g., relatively high) congestion,(e.g., perhaps because the SMS is a non-real time service, among otherreasons).

One or more barring mechanisms may be provided that may limit one ormore WTRUs, e.g., with certain configurations, to access the system,perhaps for certain services (for example as described herein).Embodiments contemplate that it may be useful to optimize the barringmechanisms. For example, CSFB may be used for voice calls andsupplementary service (SS). The voice calls may be more important thanSSs. From the WTRU's and/or the network's (e.g., the eNB's) perspective,the actual reason (e.g., the voice call or the SS) for performing CSFBmay be transparent. Embodiments recognize that the defined access classbarring (ACB) mechanism might not differentiate between barring for CSFBdue to voice call or due to SS. For the WTRUs that are in idle mode,embodiments recognize that the access control mechanisms might notdifferentiate between the voice or video (e.g., IP multimedia system(IMS) voice or video) access from other data. The voice might not beprioritized, e.g., when going from an RRC idle state to an RRC connectedstate.

A network may use service specific access control (SSAC) to suppressand/or down prioritize mobile originated (MO) accesses for MMTEL-voiceand MMTEL-video in RRC Connection Establishment. The network might notuse SSAC to disallow other MO accesses in congestion while allowing MOaccesses for MMTEL-voice and MMTEL-video. The voice over LTE (VoLTE)calls may suffer from a double barring. For example, the VoLTE calls maybe barred by SSAC and may again be barred by the regular ACB. Even if aWTRU requesting a VoLTE passes the SSAC test in the IMS level, it may besubject to the legacy ACB test in the RRC, which it might not pass. Theaccess of normal data might not be controlled with ACB, e.g., withoutimpacting voice calls. Such access barring mechanism may be in conflictwith the mechanism where VoLTE traffic may have higher priority than,for example, background traffic. The inability to differentiate betweenrequests for SMS and IP data and the insufficient barring mechanisms mayresult in increase in the number of attempts for RRC connectionestablishment. The increase in the number of attempts for RRC connectionestablishment may degrade the system, perhaps for example but notlimited to cases of congestion during which a fewer number of servicesmay be allowed by the network.

Quality of Service (QOS) class identifier (QCI) based access barring maybe provided. Access control may be applied and/or performed on one ormore QoS mechanisms, e.g., QCI. A WTRU may be aware of the QCI for oneor more, or each, of the bearers the WTRU may have. The eNB may signalthe QCI bearer that may be useful to be prioritize, perhaps while otherbearers may be backed off or assigned a lower priority. Suchprioritization of QCI bearers may cause the WTRU to send packets on aspecific bearer which may have been prioritized while backing off systemaccess requests for the data on the other bearers. Embodimentscontemplate one or more techniques for the network and/or the eNB toindicate that there is congestion in the network and/or if perhaps voiceor a certain QCI may be prioritized.

Embodiments recognize that the WTRU may have multiple access barringmechanisms at different layers, for example the AS, NAS, and IMSapplication. Embodiments contemplate one or more techniques such thatthese mechanisms may work in parallel with the QCI access barringmechanism, for example without causing any conflict.

Embodiments recognize that it may be useful for the WTRU to prioritizeits bearers carrying voice packets over other bearers in certainscenarios, for example in some emergencies, perhaps instead of the eNBinitiating the QCI based access barring. Embodiments contemplate one ormore techniques for the WTRU to request such QCI level prioritizationand/or how the network/eNB may process such requests from the WTRU.

Establishment cause(s) and/or service indication(s) per service type(s)may be provided. Establishment causes (or service indications) maydifferentiate the mobile originated (MO) requests for SMS, MO voicecommunication, CSFB for voice call, and/or CSFB for SS. Suchestablishment causes or service indications may apply to GERAN/UTRAN.For example, in UTRAN the WTRU may use a unique establishment cause orservice indication for voice calls, SMS, and/or SS. A WTRU (e.g., NAS)may set the service indication or establishment cause to MO voicecommunication and/or MO CSFB voice, perhaps for example when initiatingthe service request procedure for MO voice communication and/or MO CSFBfor voice call. The WTRU (e.g., NAS) may set the service indication orestablishment cause to CSFB SS, perhaps for example when initiating theservice request procedure for CSFB for SS. The WTRU (e.g., NAS) may setthe service indication or establishment cause to MO SMS (or MT SMS formobile terminated SMS), perhaps for example when initiating the servicerequest procedure for MO SMS (or for MT SMS). The WTRU RRC layer maysend a request for the service indicated to the network/eNB. In someembodiments, the RRC request may include the service indication, perhapsas part of an establishment cause for the service.

An eNB may be configured to filter an RRC request (e.g., to rejectcertain requests), perhaps for example based on the service requested.The eNB for example may reject requests for SMS. The eNB may reject arequest for an RRC connection, e.g., perhaps if the establishment causeis set to MO SMS, and/or if the eNB is configured to reject requests forSMS service.

The eNB may have configurations (e.g., provided via operations andmaintenance (O&M)) such that the configurations may be used to accept orreject a request. The MME may inform the eNB to reject connections forcertain specific services such as MO SMS, MO voice communication, CSFBSS, etc. The MME may do so using an S1AP procedure that maybe definedand the MME may indicate that the service be de-prioritized. This may bedone using a bitmap where a bit position may refer to a certain service(e.g., provided/facilitated by the eNB/communication network for theWTRU). The eNB may reject RRC connections, or release existingconnections that may be affected based on the information received,e.g., either from MME or via configurations. S1AP procedures (e.g., S1APoverload start) may be utilized. An MME may use a mechanism to informthe eNBs to stop access restriction (e.g., accept requests) for servicesas described herein.

The eNB may reject the WTRU's MSG1 or MSG3, for example during theRandom Access Channel (RACH) procedure. The eNB may include a cause codeto indicate that the reason for rejection may be a service (e.g., MOSMS). The WTRU may learn that the requested service (e.g., as indicatedin the corresponding establishment cause) might not be allowed, e.g.,upon a rejection of a connection by the eNB, and/or upon release of anRRC connection. The eNB might include a timer that the WTRU may use toback-off or refrain from sending requests for this service (e.g.implement barring and/or ACB for this service), perhaps for exampleuntil the timer expires and/or until an indication may received by theWTRU, e.g., via a System Information Block (SIB). The SIB may indicatethat a service may be again permitted. The eNB may carry on with therequest and/or forward the establishment cause to the MME. The MME maydecide to reject the connection based on the service indicated or thetype of service indicated. The connection rejection may be implementedat the MME. The MME may reject the NAS connection (e.g. with a ServiceReject) and may indicate the cause to the WTRU. The MME may indicate thecause with a back-off timer. The back-off timer may prohibit the WTRUfrom sending other requests for the rejected service until the timer isexpired and/or the WTRU is paged for a similar MT service. In someembodiments, the WTRU may monitor an internal timer for the back-offtime or refraining time (e.g., barring time) for sending requests forthe indicated service. The WTRU timer may be activated/started upon arejection of a connection by the eNB, upon release of an RRC connection,and/or a receipt of another signal indicating that the one or moreservices are not permitted. The WTRU timer preset value may bestatically configured and/or dynamically adjustable (e.g., as part of asignal indicating that one or more services.

Referring to FIG. 2, at 2002, a WTRU 2000 may receive an SIB from eNB2001 that may indicate one or more services is/are allowed and/or one ormore services is/are not allowed, for example MO SMS, and/or voice, etc.At 2004, for example, the NAS may send a message to the RRC, where themessage may include a service request, perhaps with a servicenotification or an establishment cause (e.g., contains a freshcall/service type such as a MO SMS, and/or a MO voice call, or thelike). At 2006, the WTRU 2000 may send an RRC connection request toestablish RRC connection(s) for the corresponding services, perhaps forexample based on the information received in the SIB and/or servicerequest. For example, a bit position for MO SMS may be set to a value(e.g., in a bit map) indicating that MO SMS is allowable (e.g., notbarred) by the eNB 2001 (and/or the communication network of which eNB2001 is a part). The WTRU 2000, perhaps for example after reading theSIB and/or bit position, may send a RRC connection request(s) for MO SMS(e.g., to the eNB/network). Alternatively or additionally, at 2008, theWTRU 2000 may refrain from sending an RRC connection request toestablish a RRC connection(s) for the corresponding services, perhapsfor example based on the information received in the SIB and/or servicerequest. For example, a bit position for MO SMS may be set to a value(e.g., in a bit map) indicating that MO SMS is not allowable (e.g.barred) by the eNB 2001 (and/or the communication network of which eNB2001 is a part). The WTRU 2000, perhaps for example after reading theSIB and/or bit position, may refrain from sending a RRC connectionrequest(s) for MO SMS (e.g., to the eNB/network). The refraining mayinclude barring the MO SMS service, which may include implementing ACBfor MO SMS, for example.

Finer (e.g, more granular) barring per service may be provided.Embodiments contemplate finer granularity of barring per specificservice (e.g., a barring mechanism may be implemented for MO voicecommunication, MO CSFB for voice, CSFB SS, and/or MO SMS). A bitmap (orother indications) may be included in the system information block (SIB)to indicate the service may be allowed (e.g., not barred) and/or mightnot be allowed (e.g., barred).

For example, the eNB (perhaps, for example, using configurations orindications from the MME as described herein) may set a bit position to1 for the corresponding service (e.g., a bit position may be known torepresent or correspond to a certain service). A bit position of 1 for acorresponding service may indicate that the service is allowed (e.g.,not barred) by the eNB/communication network. The WTRU may read thisinformation from the SIB(s), and the WTRU may establish an RRCconnections for the corresponding service(s) (e.g., as requested byanother layer—such as the NAS layer). For example, during (e.g.,relatively low) congestion, the bit position for SMS may be set to 1 andthe WTRU, after reading the SIB and/or the bit position, may send a RRCconnection requests for SMSs. Embodiments contemplate that a bit valueof 1 or 0 may be used to convey allowable (e.g., not barred) services ornot allowed (e.g. barred) services, perhaps as most suitably configuredper operator/user devices.

Also by way of example, a bit position of 0 for a corresponding servicemay indicate that the service is not allowed (e.g., barred) by theeNB/communication network. The WTRU may read this information from theSIB(s), and the WTRU may refrain from establishing an RRC connectionsfor the corresponding service(s). For example, during (e.g., relativelyhigh) congestion, the bit position for SMS may be set to 0 and the WTRU,after reading the SIB and/or the bit position, may refrain from sendingRRC connection requests for SMS. Refraining may include barring SMS,which may include applying ACB for SMS. The RRC layer may inform the NASlayer about the barring. The RRC layer may inform the NAS layer when/ifthe barring ends. The NAS layer (e.g., evolved mobility management(EMM)) may inform the entity that may trigger the request (e.g., the SMSentity) that the service may be unavailable, perhaps for some time. TheWTRU may display a corresponding message to the user.

Referring to FIG. 3, at 3002 a WTRU 3000 may receive a SIB from eNB 3001that may indicate that one or more services is/are allowed and/or one ormore services is/are not allowed, for example a MO SMS and/or voice,etc. At 3003, the WTRU 3000 may refrain from sending an RRC connectionrequest to establish a RRC connection(s) for the one or more servicesindicated as not allowed, perhaps for example based on the informationreceived in the SIB and/or service request. For example, a bit positionfor MO SMS may be set to a value (e.g., in a bit map) indicating that MOSMS is not allowable (e.g. barred) by the eNB 3001 (and/or thecommunication network of which eNB 3001 is a part). At 3004, the RRClayer may inform the NAS layer of a service specific ACB. The RRC layermay inform the NAS layer when the barring ends and/or is to end. At3006, the NAS layer (e.g., an EMM) may inform the entity that triggeredthe request (e.g. a SMS entity) that the service is unavailable (e.g.,for some time).

The network (e.g., eNB and/or MME) may inform the WTRUs that MO requestsfor SMS might not be permitted for a certain duration (e.g., asconfigured by the network), perhaps for example to increase the chancesof successful RRC connections for voice calls, reduce congestion, and/orprioritize certain services such as voice calls (e.g., MO voice, voicecommunication, IMS and/or CSFB for voice, or CSFB). Such permissioninformation may reduce RRC connection requests that may otherwise havebeen initiated for SMS, which may for example increase the chances ofsuccess for other services (e.g. voice calls that may be of higherpriority).

One or more priority levels may be provided. For example, the MT IMSand/or the MO voice communication (and/or CSFB voice) may be given ahighest priority (e.g., priority level 1). The MO voice communication,and/or the MO IMS and/or the CSFB voice may be given a lower prioritythan priority level 1 (e.g., priority level 2). The MT SMS may be givena lower priority than priority level 2 (e.g., priority level 3). The MOSMS may be given a lower priority than priority level 3 (e.g., prioritylevel 4). The MT SS may be given a lower priority than priority level 4(e.g., priority level 5). The MO SS may be given the lowest priority(e.g., priority level 6). The WTRU may be configured with this list ofpriority levels (or other similar lists). The WTRU may be informed tostart congestion control. The WTRU may use the configuration to refrainfrom requesting certain services, perhaps as informed by the eNB usingbroadcast signaling, and/or as informed via dedicated signaling from theeNB and/or the mobility management entity (MME). One or more of thecontemplated techniques may be employed in GERAN/UTRAN. One or more ofthe contemplated techniques may be employed by the WTRU in a connectedmode. One or more techniques may be employed by a Base Station System(BSS)/RNC for GERAN/UTRAN, respectively. The MME equivalent may bemobile switching center (MSC) or SGSN.

Operator policy based access control may be provided. Operator policybased access control may be realized through the use of operatorspecific policy and access control rules. The policy may be a flow basedpolicy (e.g., an IP flow based policy), a service based policy (e.g., aspecific APN), a signaling radio bearer based policy (e.g., signalingradio traffic filter or identifier), a data radio bearer based policy,and/or a QCI based policy, etc. The IP flow filters may include one ormore of an address type, a start source IP address, an end destinationIP address, a protocol type, a start source port number, an end sourceport number, a start destination port number, an end destination portnumber, an QOS, and/or an application ID. The policy may bepreconfigured on the WTRU and/or signaled to the WTRU for examplethrough control plane or through user plane. An example of signalingthrough control plane may be RRC broadcast signaling, RRC dedicatedsignaling, and/or NAS signaling, etc. An example of user plane signalingmay be signaling over the S14 interface. The ANDSF policy signalingmechanism may be used. Another example of user plane signaling mechanismmay be signaling over the IMS signaling data bearer. The policy may beenumerated and/or be represented in the form of a bitmap where one ormore, or each, element of the enumeration or the bitmap points to aspecific policy definition in the WTRU. For example, different policiescould be set for different categories of users (e.g., gold users versussilver users versus bronze users).

The policy based access control may be achieved for example throughaccess barring mechanism and/or access prioritization mechanism. Thenetwork (e.g., eNB and/or MME) may signal the policy based accesscontrol information to the WTRU to activate specific access barringpolicy or policies. The network (e.g., eNB and/or MME) may signal thepolicy based access control information to the WTRU to activate specificaccess prioritization policy or policies. The enforcement of the policymay be done in the access stratum for, for example like the enforcementof an ACB or an EAB mechanism. The enforcement of the policy may be donein one or more higher layers, for example the non-access stratum layeror IMS level like an SSAC. The enforcement of the policy may be providedin the access stratum layer and/or a higher layer, perhaps for exampledepending on the type of the traffic being access controlled. Thedefinition of the policy may include a validity area definition. Forexample, a policy may be activated by the network and/or may apply to agiven subscriber if the validity area defined for the policy in the WTRUmay include the current location of the subscriber. The policy mayinclude the time of the day for the applicability of the policy. Forexample, a policy may be activated by the network and/or may apply to agiven subscriber if the time of the day defined for the policy in theWTRU may cover the time during which the policy may be active.

A network may configure a WTRU with one or more policies. For example,there may be three policies P1 and P2 and P3 (policy annotation used forpurposes of illustration and not limitation). Policy P1 may be set forgold subscribers, policy P2 may be set for silver subscribers, andpolicy P3 may be set for bronze subscribers. For example, one or more ofthe policies P1, P2, and/or P3 may include one or more traffic flowfilters. Again by way of example, example the policy P1 may includethree IP flow filters (e.g., F1(P1), F2 (P1) and F3 (P1)). The policy P2may include three IP flow filters (e.g., F1(P2), F2(P2), F3(P2)). Thepolicy P3 may include two IP flow filters (e.g., F1(P3), F2(P3)).

An Access Network Discovery and Selection Function (ANDSF) server mayconfigure over the S14 interface, the WTRUs with P1, P2 and/or P3policy. The eNB may configure the WTRU with the policies P1, P2, and/orP3. The eNB may use dedicated RRC signaling and/or RRC broadcastsignaling. The RRC layer of the WTRU may forward the policies to theupper layer within the WTRU, perhaps for example upon receiving thepolicies P1, P2, and/or P3. The MME may signal the policies P1, P2and/or P3 to the WTRU. The NAS layer of the WTRU may forward thepolicies to other entities within the upper layer of the WTRU and/or mayforward them down to the access stratum layer within the WTRU, perhapsfor example upon receiving the policies P1, P2, and/or P3.

The WTRU may be statically pre-configured by the operator with thepolicies P1, P2, and/or P3. The preconfigured policies on the WTRU maybe updated using one of the methods described herein. The function inthe WTRU that may receive the preconfigured policies P1, P2 and/or P3may forward the policies to the NAS layer, the access stratum layer,and/or the ANDSF client on the WTRU, or other entities in the WTRU thatmay interact with the access control, e.g., the IMS layer.

The eNB may signal a bitmap, for example, [bit(P1)=1, bit(P2)=0,bit(P3)=0] to the WTRU. The bitmap may be signaled using RRC dedicatedsignaling and/or RRC broadcast signaling. For example, the eNB may usethe bit map to inform the WTRU that traffic matching the criteria ofpolicy P1 (e.g., the IP flows that may be defined in policy P1) may beprioritized for access, perhaps while traffic matching the criteria ofpolicy P2 and/or P3 may be barred from access, or assigned a lowerrelative priority than that of the P1 traffic. The eNB may control theactivation and/or deactivation of access control on the WTRU using anactivation flag. The eNB may signal the activation flag to the WTRU(s)using RRC dedicated signaling and/or RRC broadcast signaling. Forexample, perhaps as an optimization, the eNB may broadcast a priorityfactor for one or more, or each, of the policy P1, P2 and/or P3, with0≤priority factor≤1 for one or more, or each of the policies. Thenetwork (e.g., the eNB) may use the priority factor for a given policyto control the one or more WTRUs with a given policy that may beprioritized for access. The eNB may broadcast a barring factor for oneor more, or each, of the policy P1, P2 and/or P3, with 0≤barringfactor≤1 for one or more, or each, of the policies. The eNB may use thebarring factor to control the one or more WTRUs with a given policy thatmay be barred for access. The eNB may broadcast a barring time for oneor more, or each, of the policy P1, P2 and/or P3. The eNB may use thebarring time for a given policy to control how long the access for aWTRU may be barred for traffic matching the criteria defined by thatpolicy.

Other network nodes, e.g., an MME, may signal to the WTRU the policybitmap, the priority factor, the barring factor, and/or the barringtime. The MME may signal this information to the WTRU, for example usingthe NAS signaling and/or other higher layer protocol signaling. An IMSsignaling node may signal the information to the WTRU. A network nodesuch as the ANDSF server may signal the policy information to the WTRU.

While the IP flows may be used to describe the policies P1, P2 and/or P3(as in the previous example), other parameters for example QCI and/orAPN (e.g., service based access control) may be used to define thepolicies P1, P2 and/or P3. For example, P1 may include one or moreInternet Protocol (IP) flows with QCI 1, QCI 5, and/or QCI 9; P2 mayinclude one or more IP flows with QCI 3 and/or QCI 9; P3 may include anIP flow with at least QCI 9, or the like. The eNB may be configured bythe core network with the policy P1, P2 and/or P3. An eNB function maybe defined to detect IP flow filters, perhaps for example if IP flowsmay be used to describe the policies. The Quality of Service ClassIdentifier (QCI) number may indicate the level of priority, where insome embodiments for example QCI 1 may the highest priority and QCI 9may be the lowest priority.

The WTRU may use the policy based access control bitmap, the priorityfactor, the barring factor, and/or the barring time to perform accesscontrol. For example, a WTRU may receive the bitmap [bit(P1)=1,bit(P2)=0, bit(P3)=0]. The WTRU may receive an access control activationflag. The WTRU may activate access control, perhaps for example uponreceiving the access control activation flag and/or the policy bitmap.With bit (P1) set to 1, the WTRU may prioritize traffic data packetswhich match the criteria defined by policy P1. The WTRU may bar (or setto a lower relative priority other traffic than that corresponding toP1, perhaps for example while the access control may be active.

A WTRU may receive from the network the bit that corresponds to thepolicy being prioritized for access. The WTRU may receive from thenetwork the bit that may correspond to a policy to be used to the WTRUfor access. The WTRU may receive an access priority factor from thenetwork for one or more, or each, policy P1, P2 and/or P3. The WTRU maydraw a random number “rand” that may be uniformly distributed in therange 0≤rand<1. The WTRU might not prioritize for access the trafficmatching the corresponding policy, perhaps for example if the randomnumber is lower than the access priority factor received by the WTRU.The WTRU may prioritize the traffic matching the corresponding policy isfor access, perhaps for example if the random number is higher than orequal to the access priority factor. In scenarios where the trafficmight not be prioritized, the WTRU may bar (or set to a lower priority)the traffic for access for an amount of time that may, for example, bedetermined based on the received barring time that, for example, maycorrespond to the policy being evaluated.

The WTRU may receive an access barring factor for an access to thenetwork for one or more, or each, policy P1, P2 and/or P3. The WTRUmight not bar (or might not lower the priority of) the traffic matchingthe corresponding policy, perhaps for example if the random number islower than the access barring factor received by the WTRU. The WTRU maybar (or may lower the priority of) the traffic matching thecorresponding policy, perhaps for example if the random number is higherthan or equal to the access barring factor. For example, the WTRU maybar (or may lower the priority) of the traffic for an amount of timethat, for example, may be calculated based on the received barring timethat corresponds to the policy being evaluated. The WTRU may prioritizethe traffic matching the corresponding policy for access, perhaps forexample if the random number is lower than the access priority factorreceived by the WTRU. The WTRU might not prioritize the traffic matchingthe corresponding policy for access, perhaps for example if the randomnumber is higher than or equal to the access priority factor. Inscenarios in which the traffic might not be prioritized, the WTRU maybar the traffic for access (or lower the priority), perhaps for example,for an amount of time that may be determined based on the receivedbarring time that may correspond to the policy being evaluated.

The WTRU may receive an access barring factor for one or more, or each,policy P1, P2 and/or P3. The WTRU may bar the traffic matching thecorresponding policy, perhaps for example if the random number is lowerthan the access barring factor received by the WTRU. The WTRU may barthe traffic for an amount of time that may, for example, be calculatedbased on the received barring time that may correspond to the policybeing evaluated. The WTRU might not bar the traffic matching thecorresponding policy, perhaps for example if the random number is higherthan or equal to the access barring factor.

The enforcement within the WTRU of the policy described herein may berealized in the WTRU assess stratum and/or in one or more of the WTRUhigher layers, e.g., in the NAS and/or in the IMS layer.

Enhanced QCI based access barring may be provided. The WTRU may enable(e.g., implicitly enable) QCI based access control mechanism, perhapsfor example when the network may indicate that there is networkcongestion. In some embodiments, there may be an explicit indicationfrom the eNB and/or the network to enable the prioritization of one ormore QCI bearers.

In scenarios in which the network and/or eNB may explicitly prioritizevoice services, for example, among other scenarios, the network mayindicate that the bearers with a certain QCI (e.g. QCI 1) for voicemight not be backed-off, perhaps where other bearers with other QCIvalues may be backed-off and/or might not be allowed to make systemaccess (e.g., for a certain period of time). Such embodiments mayprioritize voice bearers over bearers containing other types of traffic.

One or more types of congestion indications sent and/or broadcasted bythe eNB/network may be provided. The congestions indications may enable(e.g., implicitly enable) a WTRU to prioritize certain QCI bearers. Thenetwork may broadcast the level of congestion in the SIB broadcastmessages. For example, the network may state the level of congestion inan RRC information element (IE) or SIB IE (e.g., which may be set to 1,2 or 3). Level 1 may indicate that the network is not congested. Level 2may indicate that the network is (e.g. relatively) moderately congested.Level 3 may indicate that the network is (e.g., relatively) heavilycongested. The WTRU may back-off (e.g., implicitly back-off) and/or maybar access (e.g., which may include implementing ACB) for non-voicebearers and/or may request access to the network for voice calls,perhaps for example when the WTRU may read level 3 congestion. The WTRUmay (e.g., implicitly) assume that the network may be congested, perhapsfor example when the WTRU may send an RRC request for MO data and it isrejected by the eNB. The WTRU may request access for voice calls whichmay be accepted by the network.

The network may (e.g., explicitly) indicate the WTRU to prioritize oneor more QCI bearers. This notification may be sent to the WTRU in one ormore of the following ways: sending an indication in the RRC and/or SIBmessage with the QCI value or values which have priority, sending anindication that voice and/or some other specific service may beprioritized, and/or the eNB may accept the scheduling request for dataradio bearers (DRBs) containing voice packets.

The WTRU may have one or more access barring mechanisms in place. Theaccess barring mechanism may enable the WTRU that may be in a congestednetwork scenario to not send unnecessary connection request(s) to thenetwork, which for example may aggravate the congestion situation in thenetwork. In some embodiments, the network may indicate to the WTRU touse certain mechanisms at a given point in time, for example perhaps ifother mechanisms may be available when QCI based access barring isactivated. The WTRU may deactivate one or more of the access barringmechanism. The WTRU may keep one or more, or each, of the access baringmechanisms, perhaps for example depending on the level of congestion.

For example, the WTRU may keep each, or a relatively large subset, ofthe access barring mechanisms activated, perhaps for example if thenetwork may indicate that there is Level 3 congestion in the network.The WTRU may keep apply one or more, or a smaller subset, perhaps forexample when a Level 2 congestion is indicated. The network may be ableto indicate to the WTRU the mechanisms that may be applied at a point intime.

A WTRU may ask the network to prioritize its access for voice servicesor some other services, perhaps for example when there is no congestionin the network. This might happen, for example, when the WTRU is in anemergency situation which may be indicated to the network. The networkmay activate the QCI based access class baring mechanism and/or someother access barring mechanism, perhaps for example to prioritize therequested service, e.g., a voice call. The QCI based access barring thatmay be requested by one of the WTRUs may apply to one or more, or each,of the other WTRUs under the coverage of that eNB. The voice calls maybe prioritized in that cell for a certain period of time, perhaps forexample while the emergency WTRU may be making the voice call and/orproviding information about its emergency situation. The eNB may revertback to its normal operation, perhaps for example when the WTRU that mayhave requested the access class barring ends its emergency voice call.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

What is claimed is:
 1. A method performed by a wireless transmit/receiveunit (WTRU) in communication with a communication network, the methodcomprising: receiving, at a radio resource control (RRC) layer of theWTRU, a message from a base station indicating the WTRU is subject toaccess class barring (ACB) restrictions in a cell, the message furtherindicating one or more services that are affirmatively allowable in thecell despite the ACB restrictions; generating, at a non-access stratum(NAS) layer of the WTRU, a request for a first service; passing therequest from the NAS layer of the WTRU to the RRC layer of the WTRU;determining, at the RRC layer of the WTRU, that the first service is oneof the one or more services that are indicated as affirmativelyallowable in the cell despite the ACB restrictions; and sending, by theRRC layer, a first connection request to the base station, the firstconnection request explicitly indicating that the first connectionrequest is for the first service.
 2. The method of claim 1, wherein thefirst service comprises at least one of a mobile originated (MO) voicecommunication, a circuit switched fallback (CSFB) supplementary service(SS), or a MO short message service (SMS).
 3. The method of claim 1,wherein the message includes a System Information Block (SIB).
 4. Themethod of claim 3, wherein the SIB comprises a bitmap including one ormore bit positions for indicating the one or more services asaffirmatively allowable in the cell.
 5. The method of claim 4, whereindetermining that the first service is one of the one or more servicesaffirmatively allowable is based on a value in the one or more bitpositions.
 6. The method of claim 1, further comprising: generating, atthe NAS layer of the WTRU, a request for a second service; determining,at the RRC layer of the WTRU, that the second service is not one of theone or more services that are affirmatively allowable in the cell; andrefraining from sending a second connection request to the base stationfor the second service.
 7. The method of claim 1, wherein the basestation includes an evolved NodeB (eNB).
 8. A wireless transmit/receiveunit (WTRU), comprising: a memory; and a processor configured to:receive, at a radio resource control (RRC) layer, a message from a basestation indicating that the WTRU is subject to access class barring(ACB) restrictions in a cell, the message further indicating one or moreservices that are affirmatively allowable in the cell despite the ACBrestrictions; generate, at a non-access stratum (NAS) layer, a requestfor a first service; determine, at the RRC layer, that the first serviceis one of the one or more services that are indicated as affirmativelyallowable in the cell despite the ACB restrictions; and send, by the RRClayer, a first connection request to the base station, the firstconnection request explicitly indicating that the first connectionrequest is for the first service.
 9. The WTRU of claim 8, wherein thefirst service comprises at least one of a mobile originated (MO) voicecommunication, a circuit switched fallback (CSFB) supplementary service(SS), or a MO short message service (SMS).
 10. The WTRU of claim 8,wherein the message comprises a System Information Block (SIB) includingone or more bit positions for indicating the one or more services asaffirmatively allowable in the cell.
 11. The WTRU of claim 10, whereinthe processor is further configured to determine that the first serviceis one of the one or more services that are affirmatively allowablebased on a value in the one or more bit positions.
 12. The WTRU of claim8, wherein the processor is further configured to: generate, at the NASlayer, a request for a second service; determine, at the RRC layer, thatthe second service is not one of the one or more services that areaffirmatively allowable in the cell; and refrain from sending a secondconnection request to the base station for the second service.
 13. TheWTRU of claim 8, wherein the base station includes an evolved NodeB(eNB).